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Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

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Amount of judgment or settlement awarded to (against) the entity in respect of litigation.

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Number of Businesses Disposed

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Proceeds from Previous Divestiture

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Discontinued Operations - Additional Information (Detail) $ in Millions			3 Months Ended				12 Months Ended
	Mar. 31, 2015 USD ($)	Mar. 17, 2015 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) Business	Nov. 30, 2015 USD ($)	Jun. 12, 2015 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of businesses disposed \| Business							3
Professional Services Segment [Member] \| Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from business disposals								$ 130.0
Holdback amount								$ 7.5
Holdback amount received			$ 2.4
Net gain (loss) from business disposal				$ 97.0
Working capital adjustment on business disposal			$ 1.5
Downstream Professional Services [Member] \| Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from business disposals									$ 10.0
Net gain (loss) from business disposal					$ (2.2)
Premier Utility Services, LLC [Member] \| Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from business disposals	$ 51.0					$ 51.0
Net gain (loss) from business disposal						37.1
Escrow deposit	$ 4.0					4.0
Period of escrow deposit	18 months
UtilX [Member] \| Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from business disposals		$ 40.0
Net gain (loss) from business disposal						$ 21.4
Escrow deposit		$ 0.5
Period of escrow deposit		6 months
Decrease in escrow account							$ 0.5
Legal settlement amount							$ 0.6